Fertilizer



Patented Dec. Q, 1924.

urrso sraras hA-TENT FFHZE.

ALFRED EUTCHINSON GOWQES, 0F SEWABEN, NEW JERSEY, ASSiGNG'R TO THE ELEC-TBIG SMELTING AND ALUMINUM (30., 0F CLEVELAND, @HIO, A CORPORATION OFFERTILIZER.

R0 Drawing. original appllicatien filed December 21, 1918, Serial No.267,809. Divided and this application filed May 6, 1919, Serial No.295,086. Renewed June 24, 1924.

To all whom it may concern:

Be it known that I, Amman CowLEs, a citizen of the United States, "andresident of Sewaren, in the county of Middlesex and State of New Jersey,have invented certain new and useful Improvements in Fertilizers, ofwhich the following is a specification.'

My invention relates to fertilizers, and is a division of myapplication, Serial No. 267,809, filed December 21, 1918.

It consists in designedlyusing variable proportions of lime and hydratedsilica containin more than fifteen per cent of water of hy rationobtained from di-calcium silicate to supply the deficiencies of lime andsoluble silica required for plant growth. Such silica containing variousamounts of water are securable by the action of carbonic acid and otheracids and moisture upon various simple and complex silicates, naturaland artificial.

My invention further consists in the intentional addition or formationof designed proportions of such silicates in the reparation offertilizer mixtures .or su stances, either by the addition of suchhydrated silica or such silicates and an acid, with the in-' tentionaldesign of increasing or supplying intended amounts of hydrated silica tosuch mixtures. My invention and discovery further embodies adding tosoils simple or complex calcium silicates artificially prepared, of sucha quality that the carbonic acid of the soil waters will decompose saidcompounds or mixtures with a liberation. of hydrated silica f thosehydrateg silicas that ordinarily occur in nature as minerals. Thepresence of other essential fertilizers; such as potash, iron oxide,phosphoric acid and soda in said complex silicates is not to be avoidedwhere there is suflicient allowance of calcium oxide or carbonate forthe silica in the mixture,

so that upon the action of carbonic acid can be artifi'cally re aredthat will furnish a cheap source of so uble silica.

a more soluble type than.

One method of producing the di-calcium silicate as a source of solublehydrated silica after being mixed with lime in such proportions thatthere shallv be present in the mixture two molecular weight proportionsof lime o one of silica, and such proportions of alkali metal oxide toalumina that there can be leached out of the sinter alkali aluminate,leaving an insoluble ii-calcium silicate, plus iron oxide and a variableamount of zeolitic material. The alkali aluminate can be treated byknown methods and the alkali metal oxide and alumina separated for usein their respective arts. The di-calcium silicate, before being appliedas a fertilizer or fertilizer constituent, should be pulverized orreduced to a finely divided state, say to a size to pass an 80 mesh. Thedi-calcium silicate will have a porous nature because thealkali-aluminate has been leached away from it.

One method'of preparing artificial alkalisilico-aluminate, from whichthe di-calcium silicate can be obtained, is carriedout by me on a largescale for the obtaining of alumina, for use in making the metal aluminum. Clay, saltand carbon are shaped into nace to the action of vapor ofwater, the result being alkali-silico-aluminate bricks and hydrochloricacid. The alkali-silico-aluminate is mixed with calcium oxide, orcarbonate, in such proportions that, when sintered,

'there shall be formed as a product insoluble (ii-calcium silicate andsoluble alkali aluminat/e. The proportion of lime to silica is the sameas that given above when speaking of feldspar, 'leucite and the like,and the alkali metal oxide and, alumina are obtained in the same manner.

Magnesium carbonate found in limestone is molecularly equivalent tocalcium carbonate. Magnesia (MgO) is known to act like lime inneutralizing soil acidity. It seems desirable, however, that magnesia inlime stone be not too high in quantity. Its presence raises thesintering temperature.

Hydrated calcium sillcate can be also produced by treating infusorialearth, best when high in. water of chemical combinatures.

tion with slacked lime at ordinary tempera- Infusorial earths maycontain as high as thirteen per cent of water. This reaction does nottake place with ground crystalline silica. Thus, native hydrated silica,may, by treating with slacked lime and water, produce calcium silicatessuitable for use.

Hydrated silica containing the proper amount of water of hydration maybe applied to deficient soils by adding to a fertilizer mixturedi-calcium-silicate containing variable percentages of alkali metaloxide and alumina, after the same has been subjected to naturallyoccurring acids and moisture.

I have made comparative plant growth experiments using, as a fixedfactor, equal amounts by Weight of calcium oxide content in di-calciumsilicate, in calcium carbonate, in calcium hydrate, in calcium carbonateplus hydrate of silica mixed therewith, and in calcium hydrate plushydrated silica in mixture, in soils both completely and partiallydevoid of lime, .and found that in those cases where I was supplyinghydrated silica to the soil, even as low as one quarter of a ton to theacre, such supply has greatly augmented the growth and luxuriance ofnearly all. the many plants submitted to comparative tests. Theseexperiments have been performed both in pots and on plots of land, andwith each plant comparative experiments have been made, and in manycases several times repeated. The aggregate result of this work hasproven that silica, in soluble form is needed to make up that deficiencythat exists in all soils that have been submitted to long cultivation.As said before, my di-calcium silicate is especially adapted to increasethe value of fertilizers to be used on acid or neutral soils deficientin hydrated silica.

Di-calcium silicate can also be obtained by treating silicious rockscontaining potash whereby the di-calcium silicate is loaded with quite aquantity of potassium alumi nate, with other non-harmful impurities,

and the compound substance procured is decomposable by carbonic acid andwater,

' liberating in the soils potash, lime and silica as fertilizers. Thismaterial may also be used alone or added as a constituent to otherfertilizers or fertilizer mixtures.

At the present time, soils from the decomposition of plants and manuresare known to contain hydrated silica, also artificial mixtures offertilizers, in many instances, contain it in indefinite amounts as anaccidental impurity. Liebig as early as 1840, from his investigation ofthe composition of the ashes of various plants, thought silica 1necessary as a plant food. This resulted in experiments with potassium,and sodium sili cates to supply silica to augment the growth clay,zeolites and feldspa-rs in soils, furnish a superabundance of silica andtherefore its addition as a fertilizer is unnecessary. These substancesand natural silicates are so minutely soluble that the assumption isunwarranted. By annual repeated growths of vegetation upon uncultivatedland, hydrated double silicates, while slowly degrading to clay, furnishto soil waters soluble silica. This accumulates and is held by zeolites.vegetation and humus, and in time, an abundance of the same is in suchsoils and furnishes normal amounts to successive growths. Cultivationwith exhaustion of humus and annual removal of crops, ex: hausts thesoil faster than it is replenished. Figuratively, the sponge has beenremoved that has accumulated and retained in sufiicient amount thismaterial which forms a large part of the natural skeletons of plants.

Cultivationalso accelerates this loss through facilitating sub-soildrainage. Thus it is that soil Water solutions in soils on cultivatedlands largely free from humus, have become deficient in the quantity ofsoluble silica that is needed for maximum plant growth.

Many suggestions have been made involving the fusion of lime with nativepotash minerals such as occur in granites or potash schists andgreen-sand marls, with a view to render available the potash therein forfertilizer purposes. In such attempts, it was thought necessary to usepotash minerals of high potash content and only suflicient lime todisplace the molecular weight proportions of potassa that-were in theconstitution of the potash silicatestherein. It is now thought that suchprocesses are valueless. In these attempts, the product secured from,for instance, potash, feldspar and lime, the design was to lock the limein the form of an insoluble mono-calcium aluminum-silicate, freeing thepotassa (K 0) for solution.

It was not realized that im ure felds are and other potash mineralsllicates mixed with free silica, can be treated preferably at insolubleportion of silica in the mixture, and that after such treatment, theaction of carbonic acid and moisture on the product, will cause thealkali aluminate necessarily formed to decompose with liberation ofpotassium oar- .bonate, and also will decompose all excess tion, thequantity of which inversely varies to a marked degree with temperaturesto which soil waters are naturally subjected. These substances are thehydrated feldspars or zeolites of nature. They are permutites, and whenimmersed in a mixed solution, like soil waters, they reciprocallyexchange, expecially alkali earth metal oxides and alkali metal oxides,inclusive of ammonia. These exchanges are governed by the laws of massaction as bearing upon the action of various ions, with variations oftemperature and variations of the density of different solutes. Zeolitesare recognized as valuable soil constituent v I disclaim the use ofsoluble alkali metal silicates for application to the soil or to add tofertilizer mixtures as a source of supply of soluble silica. Plantgrowth experiments, long ago abandoned, made with them, have led plantphysiologists into the error of considering the soluble types ofsilica-as non-essential in the fertilization of plants. These oldexperiments failed for a chemical reason that has not been recognized inthis art, namely: All soils fertilized, or not, that are suitable forplant growth, must contain calcium bi-carbonate or a salt of calcium.The action of soluble alkali silicates when in solution and brought incontact with calcium salts, leads to the for mation of insolublecompounds formed of lime, alkali metal oxide and silica. When these oldexperiments were made, as there was always employed an excess of lime,or

lime salt, above that necessary to form this product, such insolublesalts formed. Therefore, when the experimenters thought they werefurnishing soluble silica to the soil water, this silica was beingimmediately precipitated out and so rendered non-available to theirplants. The deductions drawn from their experiments were, therefore,misleading. These deductions have found their Way into the literature ofthis art. Locking up of the silica occurs even with clay present, orwith-zeolites in the soil, when soluble alkali silicates are used. Thesilica enters into combination to replace silica that has formerly beenleached away from zeolites during their slow process of degradation toclay. From these causes the old comparative plant growth experimentsfailed to show the value of silica hydrates. This should have beenrecognized from the art relating to themanufacture of artificial stonefrom alkali silicates or water glass and said lime compounds. Also fromthe work performed by Daubree, T. Sterry Hunt and others on the reactionof alkali silicates in the artificial formation of insoluble minerals.

Having thus fully described my invention and the mannerv in which it. isto be carried out, what I claim, is

1. A fertilizer for supplying lime and hydrated silica, the lattencontaining more than fifteen per cent of water of hydration, composed ofdi-calcium silicate containing alkali metal oxide and alumina.

2., A fertilizer material composed in large proportion of (ii-calciumsilicate containing alkali and alumina. I

3. A fertilizer constituent composed of di-calcium silicate containin asimpurities zeolite material and iron oxi e.

4. A fertilizer composed of di-calcium silicate and insoluble compoundsof a zeolitic nature and iron oxide in combination with substancescontaining potassium oxide ALFRED HUTCHI-NSON cowtns.

